Count threads of a Java program

[edw]

All,

I'm running quite a big java application on a solaris 8 machine.
All I want to know now is, how many java threads this application has.
Now, I know, that each LWP contains at least one java thread, so I can
make a lower boundary. But I can not tell, how many there really are.
I tried a lot of things like ps -L, or prstat -L ending up with a NLWP
number, but not the actual thread count.
Changing the application is also not an option, as we do not have the
source of it :-(

Is there anyone who can help with this?
Thanx a lot
EDW.

[Matthias Ernst]

edw wrote:

> All,
>
> I'm running quite a big java application on a solaris 8 machine.
> All I want to know now is, how many java threads this application has.

Send a SIGQUIT to the process (kill -QUIT <pid>). A thread dump will be
dumped to stderr or stdout. No worry, the VM will keep running ! You can
grep 'prio=' | wc -l or somesuch on that dump to count the threads. Apart
from the number, these dumps can be highly interesting for the debugging
reader...

Matthias
--
Matthias Ernst
Software Engineer

CoreMedia - Smart Content Technology

[Stephen Kellett]

In message <qoj0ivccqhgrojff1f8s562c8l0ql0apat@4ax.com>, Roedy Green
<roedy@mindprod.com> writes

>On 24 Jul 2003 13:37:25 -0700, [email]edw@gmx.at[/email] (edw) wrote or quoted :
>

>>I'm running quite a big java application on a solaris 8 machine.
>>All I want to know now is, how many java threads this application has.
>>Now, I know, that each LWP contains at least one java thread, so I can
>>make a lower boundary.

>
>You might modify the Thread constructor to add one to a count and
>display it. Then put your modified class file in rt.jar.

Write a helper DLL using JVMPI or JVMDI and count the thread creation in
that. You can printf to the console or put up your own GUI to display
the details. You'll need to be familiar with C/C++ though.

The JVMDI also has a high level Java interface, but I couldn't comment
about this.

Java tools for Windows (in beta) [url]http://www.softwareverify.com[/url]
--
Stephen Kellett
Object Media Limited [url]http://www.objmedia.demon.co.uk[/url]
RSI Information: [url]http://www.objmedia.demon.co.uk/rsi.html[/url]

[edw]

Stephen Kellett <snail@objmedia.demon.co.uk> wrote in message news:<uaDsU8H$RQI$EwgP@objmedia.demon.co.uk>...

> In message <qoj0ivccqhgrojff1f8s562c8l0ql0apat@4ax.com>, Roedy Green
> <roedy@mindprod.com> writes

> >On 24 Jul 2003 13:37:25 -0700, [email]edw@gmx.at[/email] (edw) wrote or quoted :
> >

> >>I'm running quite a big java application on a solaris 8 machine.
> >>All I want to know now is, how many java threads this application has.
> >>Now, I know, that each LWP contains at least one java thread, so I can
> >>make a lower boundary.

> >
> >You might modify the Thread constructor to add one to a count and
> >display it. Then put your modified class file in rt.jar.

>
> Write a helper DLL using JVMPI or JVMDI and count the thread creation in
> that. You can printf to the console or put up your own GUI to display
> the details. You'll need to be familiar with C/C++ though.
>
> The JVMDI also has a high level Java interface, but I couldn't comment
> about this.
>
> Java tools for Windows (in beta) [url]http://www.softwareverify.com[/url]

Thanx a lot, but programming is no option here and solaris is not very
familiar with dlls ;-)

edw.

[edw]

Matthias Ernst <matthias.ernst@coremedia.com> wrote in message news:<bfr05t$hoett$1@ID-133822.news.uni-berlin.de>...

> edw wrote:
>

> > All,
> >
> > I'm running quite a big java application on a solaris 8 machine.
> > All I want to know now is, how many java threads this application has.

>
> Send a SIGQUIT to the process (kill -QUIT <pid>). A thread dump will be
> dumped to stderr or stdout. No worry, the VM will keep running ! You can
> grep 'prio=' | wc -l or somesuch on that dump to count the threads. Apart
> from the number, these dumps can be highly interesting for the debugging
> reader...
>
> Matthias

This is a true operations solution. Worked like a charm. Thanx a lot :-)
edw.

[Sami Lakka]

If you don't want to use JVMPI or JDI you could just run the program in
debugger that shows the running threads. Graphical debuggers usually has
this functionality (for example Eclipse). You can also use the hprof
profiler
that is distributed with Sun's JVM. Just type Java -Xrunhprof
applicationToBeProfiled.
HProf dumps the profiling data of that application, and as I remember it
also shows
the thread count.

- Sami


"edw" <edw@gmx.at> wrote in message
news:84ea18d7.0307240502.70e58f82@posting.google.c om...

> All,
>
> I'm running quite a big java application on a solaris 8 machine.
> All I want to know now is, how many java threads this application has.
> Now, I know, that each LWP contains at least one java thread, so I can
> make a lower boundary. But I can not tell, how many there really are.
> I tried a lot of things like ps -L, or prstat -L ending up with a NLWP
> number, but not the actual thread count.
> Changing the application is also not an option, as we do not have the
> source of it :-(
>
> Is there anyone who can help with this?
> Thanx a lot
> EDW.